1. Field of the Invention
The invention relates to the interconnection of pipes, and more particularly to mechanical means for connecting branch pipes to a main pipe.
2. Background of the Invention
A smaller or branch pipe is often connected to extend perpendicularly from a larger or main pipe. The main pipe may have a vertical, horizontal or other orientation.
Conventional branch pipe joints have been provided by welding-in of another piece of pipe or adapter, known in the piping industry as "stubbing-in", or by using a weld saddle; or further by adding a separate fitting such as a "Tee", which may be of the mechanical or weld type. Fittings called "Crosses" are also known for joining two perpendicular branches, running in opposite directions, to a main pipe.
Such welding-in or assembly of piping with Tee or Cross fittings can require highly skilled labor and special equipment, and can be time consuming and expensive procedures. It is desirable to avoid these disadvantages.
The difficulties of welding have been avoided by the use of so-called mechanical "saddles" for attaching a branch pipe to a considerably larger main pipe, but such mechanical saddles have serious limitations. Their use is restricted to outlets that are small with respect to the main pipe size. These same saddles are designed for practical use only with standard or heavier wall pipe and have limited service life because of the compression type gaskets used in conjunction with them.
These saddles are usually held in place with a narrow strap(s) or "U" bolt(s) which do not act to reinforce the weakened outlet area and therefore require other means of reinforcement and/or support.
It is apparent that existing mechanical saddle designs do not aid in positive alignment or serve to prevent rotation of the outlet, necessitated by modern pressure piping methods.
Conventional branch and cross joint assembly devices and methods are not entirely suitable for the lighter wall thicknesses and lower strength materials used in modern piping, and are limited with respect to the ratio of diameters of main to branch pipes.